WO2009045110A1 - Electrically-driven hydraulic pump unit having an accumulator module for use in subsea control systems - Google Patents

Electrically-driven hydraulic pump unit having an accumulator module for use in subsea control systems

Info

Publication number
WO2009045110A1
WO2009045110A1 PCT/NO2008/000349 NO2008000349W WO2009045110A1 WO 2009045110 A1 WO2009045110 A1 WO 2009045110A1 NO 2008000349 W NO2008000349 W NO 2008000349W WO 2009045110 A1 WO2009045110 A1 WO 2009045110A1
Authority
WO
Grant status
Application
Patent type
Prior art keywords
hydraulic
subsea
pump
pressure
pump unit
Prior art date
Application number
PCT/NO2008/000349
Other languages
French (fr)
Inventor
Egil Eriksen
Original Assignee
Multicontrol Hydraulics As
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date

Links

Classifications

    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21BEARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B33/00Sealing or packing boreholes or wells
    • E21B33/02Surface sealing or packing
    • E21B33/03Well heads; Setting-up thereof
    • E21B33/035Well heads; Setting-up thereof specially adapted for underwater installations
    • E21B33/0355Control systems, e.g. hydraulic, pneumatic, electric, acoustic, for submerged well heads

Abstract

The invention relates to an electrically driven subsea hydraulic pump unit (1) for hydraulic power generation in a production control system, the pump unit being connected to the hydraulic supply (10A) from the surface or a subsea reservoir. The suction side of a pump (3) with a suction side accumulator (4A) is connected to the hydraulic supply (10A) of a high pressure intensifier (HPI) on the seabed installation or to a reservoir (4B) of a subsea hydraulic power unit (HPU). With a control system (9) the operation of the hydraulic pump (3) is controlled by an electric subsea motor (5) via a magnetic coupling (6). The charging of an accumulator module (2) from the pump unit to a higher fluid pressure is carried out by using the hydraulic pump (3). The downward adjustment of the pressure on the output of the accumulators is made by means of controllers (8) to a desired fluid pressure for the activation of valve systems by high hydraulic fluid consumption. Charging of the accumulators is carried out by hydraulic fluid energy in periods with sufficient electric power available from the power supply to the subsea installation. With electric operation, any emission of hydraulic fluid into the surroundings is eliminated.

Description

ELECTRICALLY-DRIVEN HYDRAULIC PUMP UNIT HAVING AN ACCUMULATOR MODULE FOR USE IN SUBSEA CONTROL SYSTEMS

The invention relates to an electrically driven hydraulic pump unit with an accumulator module for use in subsea con- trol systems, as specified in the preamble of the accompanying claim 1.

The pump unit could be used in different subsea control system solutions:

- A subsea high pressure intensifier, HPI - A subsea hydraulic power unit, HPU

- The system may also be configured to switch between operating either as an HPI or as an HPU.

The prior art is the hydraulic supply via a subsea common supply of bundled cables/tubes with electric power, signals and hydraulic lines (umbilical) from an installation/platform. Accumulators are placed on the subsea distribution system and/or on each control module belonging to the valve blocks (X-mas tree) mounted on the well head.

From the patent literature are cited as background techno- logy:

- US 6343654 Bl disclosing a unit for the local generation of hydraulic power for the operation of valves in a well intervention tool system, a so-called lower landing string assem- bly. This is clearly different from the invention of the application, in that the object is completely different and the technical implementation is different.

- US 7156169 B2 disclosing a unit for generating hydraulic power locally on a tool for installing the pipe suspension system of a subsea well in the well head equipment, and having an object corresponding to that mentioned above, but controlling only the tool and not barrier valves and disconnecting function.

- NO 314516 Bl (equivalent to GB2322652 A) disclosing a hy- draulically driven pressure intensifier for the local generation of hydraulic power for the operation of a downhole valve, in which there may be used, among other things, a lower pressure rating on the hydraulic supply line, actuator and also the well head equipment. This is clearly different from the invention of the application in that the object is completely different and the technical implementation of the equipment is different.

- US 6216784 Bl disclosing a unit for generating hydraulic power for the operation of downhole tools in connection with well operations, with a completely different object and technical implementation than that of the application, which is placed in the open sea on a subsea installation as part of a permanent production control system.

- US 6192680 Bl disclosing a system meant in particular as an alternative for accumulating hydraulic energy for a control system intended for blowout preventers, BOPs, in drilling at great water depths. It is envisaged to use the hydrostatic water pressure instead of gas pressure from accumulation sys- terns in the conventional manner. A return from the hydraulic system runs into a collapse-resistant hydraulic line extend- ing to the surface, so that the system gets to work with a differential pressure.

- DE 2813768 Al, available also in English, GB 1595529, among other languages, disclosing on a conceptual level a produc- tion control system which is to be independent of electric and hydraulic power supplies from the surface. It is described to include a pump function and electric power supply from a radioactive isotope.

- US 4880060 disclosing a hydraulic control system for oper- ating valves on a well intervention tool system, a so-called lower landing string assembly, which is used in a subsea well operation. This is clearly different from the invention of the application in that the use and technical implementation of the equipment are different.

- US 6702025 B2 including, among other things, a pressure in- tensifier which is placed on a subsea well head/subsea installation and which is connected to the hydraulic system, a hydraulic pump driven by an electromotor increasing the hydraulic pressure, and a hydraulic control device for activat- ing subsea downhole well equipment. This is clearly different from the invention of the application in that the application and technical implementation of the equipment are different. The invention has an object corresponding to that of NO 314516 Bl; the difference is the electric operation.

- US 6651749 Bl, WO 2006/039719 A2 , WO 01/65061 Al, US

5897095, US 6269874 Bl and NO 159679 C all disclosing different fluid pressure intensifiers in connection with control and regulating systems for subsea well equipment for objects different from that of the invention of the application and different technical implementations of the equipment.

There are great distances and relatively small dimensions in the hydraulic supply lines from the shore or platform. This entails that it takes time to replenish the hydraulic unit of the platform when hydraulic energy is drawn from the accumulator system on the subsea installation.

When the hydraulic capacity of the hydraulic supply to a sub- sea installation is too small, this will lead to a delayed start-up of the wells after a production shut-down, with production lost. There is a limit to how large a distance there may be between a subsea installation and the power supply at the surface, so that local generation of hydraulic power under water will be an alternative to today's technique.

The accumulator capacity at the subsea installations is often poorly utilized. The accumulators operate within a narrow pressure range. The reason is that the pulse-operated control valves with hydraulic latch in the subsea control modules, directing actuating pressure to valve actuators at the subsea equipment, need a high operational pressure to ensure that they will not fall out of the latching function. This restricts how much energy can be drained from the accumulators before the pressure gets below a critical level .

Both a hydraulic pressure intensifier (HPI) , with hydraulic supply from a platform/shore and under water, and hydraulic power generation (HPU) can use a subsea electrically driven pump which takes the hydraulic supply pressure up to the de- sired pressure and charges a set of accumulators locally on a subsea installation. The pressure downstream of the accumulators is adjusted down to the desired level.

The invention is an electrically driven pump module (1) with electric operation, which may be included in an HPI applica- tion or an HPU application or a combination thereof.

Reference is made to figure 1, schematics, and figure 2, a conceptual sketch of the invention.

Subsea HPI :

An HPI has for its purpose to make it possible for hydraulic energy to be drawn from the accumulator package 2 of a subsea pressure intensifier when there is high consumption in the start-up of the subsea wells, and with electric operation consumption of hydraulic fluid into the sea is avoided, which is a problem in the prior art which is hydraulically driven pressure intensifiers . Any emission of hydraulic fluid into the sea requires an emission permit.

In a subsea HPI application the pressure from the hydraulic distribution system is intensified and the pump module charges a set of subsea accumulators 2. In an HPI application the supply pressure from the surface is connected to the pump 3 via a suction side accumulator 4A. A controller 8 on the output from the pump module provides for the energy of the associated accumulators 2 to be released only when the consumption at the subsea installation makes the system pressure fall below the set point of the controller 8.

The return system is independent of the HPI and either discharges directly into the sea or is taken back to the surface via a return line in the umbilical extending between the platform/shore and the subsea installation. The return system is not shown in the accompanying figures.

Subsea HPU:

A subsea HPU solution with local hydraulic power generation and storing of hydraulic power gives the same advantages as an HPI solution with respect to quicker start-up of the wells after a shut-down. In an HPU application there is a closed subsea hydraulic system without supply and return lines back to a platform or to shore. The return from the system goes to a subsea return reservoir which is part of the HPU system - not shown in figure 1.

When the electrically driven pump unit 1 is included in a subsea HPU solution, it will suck hydraulic fluid from a sub- sea reservoir 4B instead of from a supply line from shore or from a platform. The hydraulic fluid, which is returned from the control modules of the well equipment, is carried into a HPU return reservoir. The hydraulic fluid is filtered and water, if any, is removed in a separate circuit before the fluid is pumped into the supply reservoir 4B, which is connected to the suction side of the pump.

Electric operation of the pump prevents the emission of hydraulic fluid from the operation of the pump in the same manner as in an HPI application. With an HPU solution in which the hydraulic system is a closed circuit locally on the sub- sea installation, a saving is achieved in costs for supply and return lines in an umbilical, which is the prior art.

Local power generation enables operation of hydraulic control systems over larger distances than what is possible today.

A subsea HPU with a closed hydraulic system gives great freedom in the choice of hydraulic fluid as the hydraulic fluid is not released into the sea. Water-based hydraulic fluid is widely used today because of environmental restrictions on the release of hydraulic fluid into the sea. It is usual to release water-based fluids into the sea, whereas mineral oils are taken back to the installation by way of a return line. When environmental requirements connected to emissions may be disregarded, it is not necessary to make a compromise which will be of consequence to the lubricity and bactericidal properties of the hydraulic fluid.

Switching between the operation as a subsea HPU and HPI func- tion :

The system may also be configured to switch between operating either as an HPI or as an HPU. Then there will be an isolating valve 15 protecting the tank from pressure from the dis- tribution 1OA. The tank will also be protected from overpressure by a safety valve 16.

The present application relates to an electrically driven hydraulic pump unit with an accumulator module for use in a subsea HPI or HPU application, integrated in a subsea control system, and the pump unit is characterized by the characteristics set forth in the claims.

Figure 1 shows schematically an example of a hydraulic structure with an electric motor 5 driving, via a magnet coupling 6, a hydraulic pump 3 with a suction side accumulator 4A for an HPI application, alternatively a subsea reservoir 4B for an HPU application, accumulator module 2, check valves 7 and pressure controller 8.

Figure 2 shows the pump unit 1 which is included in an HPI or HPU system, and which is placed in a suitable position on the subsea installation. An electric motor 5 controlled by a control system 9 drives a hydraulic pump 3 by way of a magnet coupling 6 which provides for power transmission without dynamic seals subject to wear. The suction side accumulator 4A is charged by the supply pressure from the platform/shore 1OA in an HPI solution. Alternatively, the suction side of the pump will be connected to a subsea reservoir 4B in an HPU solution. The input pressure to the pump will be relatively high in an HPI solution, whereas the input pressure in an HPU solution will correspond to the water pressure at the rele- vant water depth. The magnet coupling 6 for an HPI application should therefore be dimensioned for the relevant differential pressure between the pump chamber and the pressure- compensated 15 chamber of the electromotor 5 in an HPI configuration.

The pump unit 1 may be connected to the hydraulic system 1OA and 1OB on the seabed installation via two hoses with ROV- operated (ROV = Remote-Operated Vehicle) couplings 11 and 13. There are two ROV-operated isolating valves 12 and 14 at these connection points.

The suction side of the pump 3, which has a suction side accumulator 4A for stable supply, is connected to the supply pressure from the hydraulic distribution 1OA on the seabed installation in an HPI application, or to the reservoir 4B in a subsea HPU application. The pump 3 charges the accumulator module 2 of the pump unit 1 to the desired pressure. There are controllers 8 on the output of the accumulator module 2. The output pressure from the accumulator module 2 is adjusted down to a desired pressure, and by great consumption the system pressure will fall to a level at which the controllers 8 will release the stored energy into the rest of the system.

Claims

C l a i m
1. An electrically driven subsea hydraulic pump unit (1) for the generation of hydraulic power and storing of hydraulic energy in a production control system, the 5 pump unit (1) being connected to the hydraulic supply (10A) from the surface or a local subsea reservoir, and the suction side of the pump (3) with a suction side accumulator (4A) being connected to the hydraulic fluid supply (10A) from the surface to a high pressure io intensifier (HPI) on the seabed installation or to the subsea reservoir (4B) of a hydraulic power unit (HPU) , c h a r a c t e r i z e d i n that with a control system (9) the operation of the hydraulic pump (3) is controlled by an electric subsea motor (5) via a mag- i5 net coupling (6) , that the charging of an accumulator module (2) from the pump unit to a higher fluid pressure is carried out by using the hydraulic pump (3), the downward adjustment of the pressure on the output of the accumulators is made by means of controllers
20 (8) to a desired fluid pressure for activation of valve systems on the subsea installation by high hydraulic fluid consumption, and that charging of the accumulators is carried out by hydraulic fluid energy in periods with sufficient electric power available
25 from the power supply to the subsea installation, without any emission of hydraulic fluid into the surroundings .
PCT/NO2008/000349 2007-10-05 2008-10-03 Electrically-driven hydraulic pump unit having an accumulator module for use in subsea control systems WO2009045110A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
NO20075029 2007-10-05
NO20075029 2007-10-05

Publications (1)

Publication Number Publication Date
WO2009045110A1 true true WO2009045110A1 (en) 2009-04-09

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Family Applications (1)

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Country Status (1)

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Cited By (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7900444B1 (en) 2008-04-09 2011-03-08 Sustainx, Inc. Systems and methods for energy storage and recovery using compressed gas
US7958731B2 (en) 2009-01-20 2011-06-14 Sustainx, Inc. Systems and methods for combined thermal and compressed gas energy conversion systems
US7963110B2 (en) 2009-03-12 2011-06-21 Sustainx, Inc. Systems and methods for improving drivetrain efficiency for compressed gas energy storage
US8037678B2 (en) 2009-09-11 2011-10-18 Sustainx, Inc. Energy storage and generation systems and methods using coupled cylinder assemblies
US8046990B2 (en) 2009-06-04 2011-11-01 Sustainx, Inc. Systems and methods for improving drivetrain efficiency for compressed gas energy storage and recovery systems
US8104274B2 (en) 2009-06-04 2012-01-31 Sustainx, Inc. Increased power in compressed-gas energy storage and recovery
US8117842B2 (en) 2009-11-03 2012-02-21 Sustainx, Inc. Systems and methods for compressed-gas energy storage using coupled cylinder assemblies
US8171728B2 (en) 2010-04-08 2012-05-08 Sustainx, Inc. High-efficiency liquid heat exchange in compressed-gas energy storage systems
US8191362B2 (en) 2010-04-08 2012-06-05 Sustainx, Inc. Systems and methods for reducing dead volume in compressed-gas energy storage systems
US8225606B2 (en) 2008-04-09 2012-07-24 Sustainx, Inc. Systems and methods for energy storage and recovery using rapid isothermal gas expansion and compression
US8234863B2 (en) 2010-05-14 2012-08-07 Sustainx, Inc. Forming liquid sprays in compressed-gas energy storage systems for effective heat exchange
US8240140B2 (en) 2008-04-09 2012-08-14 Sustainx, Inc. High-efficiency energy-conversion based on fluid expansion and compression
US8240146B1 (en) 2008-06-09 2012-08-14 Sustainx, Inc. System and method for rapid isothermal gas expansion and compression for energy storage
US8250863B2 (en) 2008-04-09 2012-08-28 Sustainx, Inc. Heat exchange with compressed gas in energy-storage systems
CN102971487A (en) * 2010-06-22 2013-03-13 韦特柯格雷斯堪的纳维亚有限公司 Differential pressure controlled motor and pump barrier fluids pressure regulation system
US8448433B2 (en) 2008-04-09 2013-05-28 Sustainx, Inc. Systems and methods for energy storage and recovery using gas expansion and compression
US8474255B2 (en) 2008-04-09 2013-07-02 Sustainx, Inc. Forming liquid sprays in compressed-gas energy storage systems for effective heat exchange
US8479505B2 (en) 2008-04-09 2013-07-09 Sustainx, Inc. Systems and methods for reducing dead volume in compressed-gas energy storage systems
US8495872B2 (en) 2010-08-20 2013-07-30 Sustainx, Inc. Energy storage and recovery utilizing low-pressure thermal conditioning for heat exchange with high-pressure gas
EP2620585A1 (en) * 2012-01-26 2013-07-31 Vetco Gray Controls Limited Communicaton in a subsea well control system
US8539763B2 (en) 2011-05-17 2013-09-24 Sustainx, Inc. Systems and methods for efficient two-phase heat transfer in compressed-air energy storage systems
US8578708B2 (en) 2010-11-30 2013-11-12 Sustainx, Inc. Fluid-flow control in energy storage and recovery systems
WO2014015903A1 (en) 2012-07-25 2014-01-30 Statoil Petroleum As Subsea hydraulic power unit
WO2013110979A3 (en) * 2012-01-23 2014-02-13 Obs Technology As Intermediate storage
US8667792B2 (en) 2011-10-14 2014-03-11 Sustainx, Inc. Dead-volume management in compressed-gas energy storage and recovery systems
US8677744B2 (en) 2008-04-09 2014-03-25 SustaioX, Inc. Fluid circulation in energy storage and recovery systems
US8733095B2 (en) 2008-04-09 2014-05-27 Sustainx, Inc. Systems and methods for efficient pumping of high-pressure fluids for energy
DE102013214736A1 (en) * 2013-07-29 2015-02-19 Eagleburgmann Germany Gmbh & Co. Kg Downhole assembly with magnetic clutch and pressure compensation
EP2697480A4 (en) * 2011-04-15 2015-10-28 Kongsberg Oil & Gas Technologies As A subsea cooling apparatus, and a separately retrievable submersible pump module for a submerged heat exchanger
US9822600B2 (en) * 2012-11-07 2017-11-21 Transocean Sedco Forex Ventures Limited Subsea energy storage for well control equipment
WO2018089173A1 (en) * 2016-11-14 2018-05-17 Chevron U.S.A. Inc. Subsea variable frequency drive and motor assembly

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050178560A1 (en) * 2004-02-18 2005-08-18 Fmc Technologies, Inc. System for controlling a hydraulic actuator, and methods of using same
US20050178557A1 (en) * 2004-02-18 2005-08-18 Fmc Technologies, Inc. Electric-hydraulic power unit
US20060102357A1 (en) * 2004-11-17 2006-05-18 Williams Michael R Electric hydraulic power unit and method of using same
WO2006059223A2 (en) * 2004-12-03 2006-06-08 Vetco Gray Scandinavia As Electro-hydraulic process control system and method

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050178560A1 (en) * 2004-02-18 2005-08-18 Fmc Technologies, Inc. System for controlling a hydraulic actuator, and methods of using same
US20050178557A1 (en) * 2004-02-18 2005-08-18 Fmc Technologies, Inc. Electric-hydraulic power unit
US20060102357A1 (en) * 2004-11-17 2006-05-18 Williams Michael R Electric hydraulic power unit and method of using same
WO2006059223A2 (en) * 2004-12-03 2006-06-08 Vetco Gray Scandinavia As Electro-hydraulic process control system and method

Cited By (46)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8225606B2 (en) 2008-04-09 2012-07-24 Sustainx, Inc. Systems and methods for energy storage and recovery using rapid isothermal gas expansion and compression
US8250863B2 (en) 2008-04-09 2012-08-28 Sustainx, Inc. Heat exchange with compressed gas in energy-storage systems
US8479505B2 (en) 2008-04-09 2013-07-09 Sustainx, Inc. Systems and methods for reducing dead volume in compressed-gas energy storage systems
US8713929B2 (en) 2008-04-09 2014-05-06 Sustainx, Inc. Systems and methods for energy storage and recovery using compressed gas
US8240140B2 (en) 2008-04-09 2012-08-14 Sustainx, Inc. High-efficiency energy-conversion based on fluid expansion and compression
US7900444B1 (en) 2008-04-09 2011-03-08 Sustainx, Inc. Systems and methods for energy storage and recovery using compressed gas
US8763390B2 (en) 2008-04-09 2014-07-01 Sustainx, Inc. Heat exchange with compressed gas in energy-storage systems
US8733094B2 (en) 2008-04-09 2014-05-27 Sustainx, Inc. Systems and methods for energy storage and recovery using rapid isothermal gas expansion and compression
US8627658B2 (en) 2008-04-09 2014-01-14 Sustainx, Inc. Systems and methods for energy storage and recovery using rapid isothermal gas expansion and compression
US8733095B2 (en) 2008-04-09 2014-05-27 Sustainx, Inc. Systems and methods for efficient pumping of high-pressure fluids for energy
US8677744B2 (en) 2008-04-09 2014-03-25 SustaioX, Inc. Fluid circulation in energy storage and recovery systems
US8209974B2 (en) 2008-04-09 2012-07-03 Sustainx, Inc. Systems and methods for energy storage and recovery using compressed gas
US8474255B2 (en) 2008-04-09 2013-07-02 Sustainx, Inc. Forming liquid sprays in compressed-gas energy storage systems for effective heat exchange
US8448433B2 (en) 2008-04-09 2013-05-28 Sustainx, Inc. Systems and methods for energy storage and recovery using gas expansion and compression
US8240146B1 (en) 2008-06-09 2012-08-14 Sustainx, Inc. System and method for rapid isothermal gas expansion and compression for energy storage
US8234862B2 (en) 2009-01-20 2012-08-07 Sustainx, Inc. Systems and methods for combined thermal and compressed gas energy conversion systems
US7958731B2 (en) 2009-01-20 2011-06-14 Sustainx, Inc. Systems and methods for combined thermal and compressed gas energy conversion systems
US8122718B2 (en) 2009-01-20 2012-02-28 Sustainx, Inc. Systems and methods for combined thermal and compressed gas energy conversion systems
US7963110B2 (en) 2009-03-12 2011-06-21 Sustainx, Inc. Systems and methods for improving drivetrain efficiency for compressed gas energy storage
US8046990B2 (en) 2009-06-04 2011-11-01 Sustainx, Inc. Systems and methods for improving drivetrain efficiency for compressed gas energy storage and recovery systems
US8479502B2 (en) 2009-06-04 2013-07-09 Sustainx, Inc. Increased power in compressed-gas energy storage and recovery
US8104274B2 (en) 2009-06-04 2012-01-31 Sustainx, Inc. Increased power in compressed-gas energy storage and recovery
US8468815B2 (en) 2009-09-11 2013-06-25 Sustainx, Inc. Energy storage and generation systems and methods using coupled cylinder assemblies
US8037678B2 (en) 2009-09-11 2011-10-18 Sustainx, Inc. Energy storage and generation systems and methods using coupled cylinder assemblies
US8109085B2 (en) 2009-09-11 2012-02-07 Sustainx, Inc. Energy storage and generation systems and methods using coupled cylinder assemblies
US8117842B2 (en) 2009-11-03 2012-02-21 Sustainx, Inc. Systems and methods for compressed-gas energy storage using coupled cylinder assemblies
US8245508B2 (en) 2010-04-08 2012-08-21 Sustainx, Inc. Improving efficiency of liquid heat exchange in compressed-gas energy storage systems
US8171728B2 (en) 2010-04-08 2012-05-08 Sustainx, Inc. High-efficiency liquid heat exchange in compressed-gas energy storage systems
US8661808B2 (en) 2010-04-08 2014-03-04 Sustainx, Inc. High-efficiency heat exchange in compressed-gas energy storage systems
US8191362B2 (en) 2010-04-08 2012-06-05 Sustainx, Inc. Systems and methods for reducing dead volume in compressed-gas energy storage systems
US8234863B2 (en) 2010-05-14 2012-08-07 Sustainx, Inc. Forming liquid sprays in compressed-gas energy storage systems for effective heat exchange
CN102971487A (en) * 2010-06-22 2013-03-13 韦特柯格雷斯堪的纳维亚有限公司 Differential pressure controlled motor and pump barrier fluids pressure regulation system
US8495872B2 (en) 2010-08-20 2013-07-30 Sustainx, Inc. Energy storage and recovery utilizing low-pressure thermal conditioning for heat exchange with high-pressure gas
US8578708B2 (en) 2010-11-30 2013-11-12 Sustainx, Inc. Fluid-flow control in energy storage and recovery systems
EP2697480A4 (en) * 2011-04-15 2015-10-28 Kongsberg Oil & Gas Technologies As A subsea cooling apparatus, and a separately retrievable submersible pump module for a submerged heat exchanger
US8806866B2 (en) 2011-05-17 2014-08-19 Sustainx, Inc. Systems and methods for efficient two-phase heat transfer in compressed-air energy storage systems
US8539763B2 (en) 2011-05-17 2013-09-24 Sustainx, Inc. Systems and methods for efficient two-phase heat transfer in compressed-air energy storage systems
US8667792B2 (en) 2011-10-14 2014-03-11 Sustainx, Inc. Dead-volume management in compressed-gas energy storage and recovery systems
WO2013110979A3 (en) * 2012-01-23 2014-02-13 Obs Technology As Intermediate storage
US9657553B2 (en) 2012-01-23 2017-05-23 Obs Technology As Intermediate storage
US20150068606A1 (en) * 2012-01-23 2015-03-12 Obs Technology As Intermediate Storage
EP2620585A1 (en) * 2012-01-26 2013-07-31 Vetco Gray Controls Limited Communicaton in a subsea well control system
WO2014015903A1 (en) 2012-07-25 2014-01-30 Statoil Petroleum As Subsea hydraulic power unit
US9822600B2 (en) * 2012-11-07 2017-11-21 Transocean Sedco Forex Ventures Limited Subsea energy storage for well control equipment
DE102013214736A1 (en) * 2013-07-29 2015-02-19 Eagleburgmann Germany Gmbh & Co. Kg Downhole assembly with magnetic clutch and pressure compensation
WO2018089173A1 (en) * 2016-11-14 2018-05-17 Chevron U.S.A. Inc. Subsea variable frequency drive and motor assembly

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